Re: [PATCH] DynamicTablesPkg: Allow multiple top level physical nodes

["Jeff Brasen" <jbrasen@nvidia.com>]

Just to clarify you are suggesting that all CPU nodes generated via this with have an outer processor container? I am fine with that but was concerned with a change in behavior to other platforms in case they are expecting the CPUs to just be under \SB.C00x instead of \SB.C000.C00x

-Jeff


> -----Original Message-----
> From: Pierre Gondois <pierre.gondois@arm.com>
> Sent: Thursday, February 2, 2023 5:03 AM
> To: Jeff Brasen <jbrasen@nvidia.com>; devel@edk2.groups.io
> Cc: Sami.Mujawar@arm.com; Alexei.Fedorov@arm.com;
> quic_llindhol@quicinc.com; ardb+tianocore@kernel.org
> Subject: Re: [PATCH] DynamicTablesPkg: Allow multiple top level physical
> nodes
> 
> External email: Use caution opening links or attachments
> 
> 
> Hello Jeff,
> I think it's ok to make this the generic case and remove the Pcd to enable it.
> Cf ACPI 6.5, 5.2.30.1 Processor hierarchy node structure (Type 0):
> 
> "Multiple trees may be described, covering for example multiple packages.
> For the root of a tree, the parent pointer should be 0."
> and
> "Each valid processor must belong to exactly one package. That is, the leaf
> must itself be a physical package or have an ancestor marked as a physical
> package."
> 
> so this original comment is incorrect:
> """
> // It is assumed that there is one unique CM_ARM_PROC_HIERARCHY_INFO
> // structure with no ParentToken and the
> EFI_ACPI_6_3_PPTT_PACKAGE_PHYSICAL
> // flag set. All other CM_ARM_PROC_HIERARCHY_INFO are non-physical and
> // have a ParentToken.
> """
> 
> On 2/1/23 17:42, Jeff Brasen wrote:
> > In SSDT CPU topology generator allow for multiple top level physical
> > nodes as would be seen with a multi-socket system. This will be auto
> > detected if there are more then one physical device and there is a new
> > PCD to enable forcing of a top level processor container to allow for
> > consistency for systems that can be either single or multi socket.
> >
> > Signed-off-by: Jeff Brasen <jbrasen@nvidia.com>
> > ---
> >   DynamicTablesPkg/DynamicTablesPkg.dec         |  3 +
> >   .../SsdtCpuTopologyGenerator.c                | 66 ++++++++++---------
> >   .../SsdtCpuTopologyLibArm.inf                 |  4 ++
> >   3 files changed, 41 insertions(+), 32 deletions(-)
> >
> > diff --git a/DynamicTablesPkg/DynamicTablesPkg.dec
> > b/DynamicTablesPkg/DynamicTablesPkg.dec
> > index adc2e67cbf..a061b70322 100644
> > --- a/DynamicTablesPkg/DynamicTablesPkg.dec
> > +++ b/DynamicTablesPkg/DynamicTablesPkg.dec
> > @@ -63,5 +63,8 @@
> >     # Use PCI segment numbers as UID
> >
> >
> gEdkiiDynamicTablesPkgTokenSpaceGuid.PcdPciUseSegmentAsUid|FALSE|B
> OOLE
> > AN|0x40000009
> >
> > +  # Force top level container for single socket devices
> > +
> gEdkiiDynamicTablesPkgTokenSpaceGuid.PcdForceTopLevelProcessorContai
> > + ner|FALSE|BOOLEAN|0x4000000A
> > +
> >   [Guids]
> >     gEdkiiDynamicTablesPkgTokenSpaceGuid = { 0xab226e66, 0x31d8,
> > 0x4613, { 0x87, 0x9d, 0xd2, 0xfa, 0xb6, 0x10, 0x26, 0x3c } } diff
> > --git
> >
> a/DynamicTablesPkg/Library/Acpi/Arm/AcpiSsdtCpuTopologyLibArm/SsdtCp
> uT
> > opologyGenerator.c
> >
> b/DynamicTablesPkg/Library/Acpi/Arm/AcpiSsdtCpuTopologyLibArm/SsdtCp
> uT
> > opologyGenerator.c
> > index c24da8ec71..58f86ff508 100644
> > ---
> >
> a/DynamicTablesPkg/Library/Acpi/Arm/AcpiSsdtCpuTopologyLibArm/SsdtCp
> uT
> > opologyGenerator.c
> > +++
> b/DynamicTablesPkg/Library/Acpi/Arm/AcpiSsdtCpuTopologyLibArm/Ssdt
> > +++ CpuTopologyGenerator.c
> > @@ -22,6 +22,7 @@
> >   #include <Library/AcpiHelperLib.h>
> >   #include <Library/TableHelperLib.h>
> >   #include <Library/AmlLib/AmlLib.h>
> > +#include <Library/PcdLib.h>
> >   #include <Protocol/ConfigurationManagerProtocol.h>
> >
> >   #include "SsdtCpuTopologyGenerator.h"
> > @@ -814,7 +815,8 @@ CreateAmlProcessorContainer (
> >                                         Protocol Interface.
> >     @param [in] NodeToken               Token of the
> CM_ARM_PROC_HIERARCHY_INFO
> >                                         currently handled.
> > -                                      Cannot be CM_NULL_TOKEN.
> > +                                      CM_NULL_TOKEN if top level container
> > +                                      should be created.
> >     @param [in] ParentNode              Parent node to attach the created
> >                                         node to.
> >     @param [in,out] ProcContainerIndex  Pointer to the current
> > processor container @@ -841,12 +843,12 @@ CreateAmlCpuTopologyTree
> (
> >     AML_OBJECT_NODE_HANDLE  ProcContainerNode;
> >     UINT32                  Uid;
> >     UINT16                  Name;
> > +  UINT32                  NodeFlags;
> >
> >     ASSERT (Generator != NULL);
> >     ASSERT (Generator->ProcNodeList != NULL);
> >     ASSERT (Generator->ProcNodeCount != 0);
> >     ASSERT (CfgMgrProtocol != NULL);
> > -  ASSERT (NodeToken != CM_NULL_TOKEN);
> >     ASSERT (ParentNode != NULL);
> >     ASSERT (ProcContainerIndex != NULL);
> >
> > @@ -893,8 +895,14 @@ CreateAmlCpuTopologyTree (
> >         } else {
> >           // If this is not a Cpu, then this is a processor container.
> >
> > +        NodeFlags = Generator->ProcNodeList[Index].Flags;
> > +        // Allow physical property for top level nodes
> > +        if (NodeToken == CM_NULL_TOKEN) {
> > +          NodeFlags &= ~EFI_ACPI_6_3_PPTT_PACKAGE_PHYSICAL;
> > +        }
> > +
> 
> Even though it was never encountered so far, it should also be possible to
> have a physical package consisting of only one CPU. So I guess it would be
> better to create a function to check the flags, whether the ProcNode is a CPU
> or a cluster.
> 
> I attached a Wip patch base on your work where such function is created.
> Feel free to take it/modify it at your will.
> 
> >           // Acpi processor Id for clusters is not handled.
> > -        if ((Generator->ProcNodeList[Index].Flags &
> PPTT_PROCESSOR_MASK) !=
> > +        if ((NodeFlags & PPTT_PROCESSOR_MASK) !=
> >               PPTT_CLUSTER_PROCESSOR_MASK)
> >           {
> >             DEBUG ((
> > @@ -973,10 +981,10 @@ CreateTopologyFromProcHierarchy (
> >     IN        AML_OBJECT_NODE_HANDLE                        ScopeNode
> >     )
> >   {
> > -  EFI_STATUS  Status;
> > -  UINT32      Index;
> > -  UINT32      TopLevelProcNodeIndex;
> > -  UINT32      ProcContainerIndex;
> > +  EFI_STATUS       Status;
> > +  UINT32           Index;
> > +  CM_OBJECT_TOKEN  TopLevelToken;
> > +  UINT32           ProcContainerIndex;
> >
> >     ASSERT (Generator != NULL);
> >     ASSERT (Generator->ProcNodeCount != 0); @@ -984,8 +992,8 @@
> > CreateTopologyFromProcHierarchy (
> >     ASSERT (CfgMgrProtocol != NULL);
> >     ASSERT (ScopeNode != NULL);
> >
> > -  TopLevelProcNodeIndex = MAX_UINT32;
> > -  ProcContainerIndex    = 0;
> > +  TopLevelToken      = CM_NULL_TOKEN;
> > +  ProcContainerIndex = 0;
> >
> >     Status = TokenTableInitialize (Generator, Generator->ProcNodeCount);
> >     if (EFI_ERROR (Status)) {
> > @@ -993,33 +1001,27 @@ CreateTopologyFromProcHierarchy (
> >       return Status;
> >     }
> >
> > -  // It is assumed that there is one unique
> > CM_ARM_PROC_HIERARCHY_INFO
> > -  // structure with no ParentToken and the
> > EFI_ACPI_6_3_PPTT_PACKAGE_PHYSICAL
> > -  // flag set. All other CM_ARM_PROC_HIERARCHY_INFO are non-physical
> > and
> > -  // have a ParentToken.
> > -  for (Index = 0; Index < Generator->ProcNodeCount; Index++) {
> > -    if ((Generator->ProcNodeList[Index].ParentToken ==
> CM_NULL_TOKEN) &&
> > -        (Generator->ProcNodeList[Index].Flags &
> > -         EFI_ACPI_6_3_PPTT_PACKAGE_PHYSICAL))
> > -    {
> > -      if (TopLevelProcNodeIndex != MAX_UINT32) {
> > -        DEBUG ((
> > -          DEBUG_ERROR,
> > -          "ERROR: SSDT-CPU-TOPOLOGY: Top level
> CM_ARM_PROC_HIERARCHY_INFO "
> > -          "must be unique\n"
> > -          ));
> > -        ASSERT (0);
> > -        goto exit_handler;
> > -      }
> > +  if (!PcdGetBool (PcdForceTopLevelProcessorContainer)) {
> > +    for (Index = 0; Index < Generator->ProcNodeCount; Index++) {
> > +      if ((Generator->ProcNodeList[Index].ParentToken ==
> CM_NULL_TOKEN) &&
> > +          (Generator->ProcNodeList[Index].Flags &
> > +           EFI_ACPI_6_3_PPTT_PACKAGE_PHYSICAL))
> > +      {
> > +        // Multi-socket detected, using top level containers
> > +        if (TopLevelToken != CM_NULL_TOKEN) {
> > +          TopLevelToken = CM_NULL_TOKEN;
> > +          break;
> > +        }
> >
> > -      TopLevelProcNodeIndex = Index;
> > -    }
> > -  } // for
> > +        TopLevelToken = Generator->ProcNodeList[Index].Token;
> > +      }
> > +    } // for
> > +  }
> >
> >     Status = CreateAmlCpuTopologyTree (
> >                Generator,
> >                CfgMgrProtocol,
> > -             Generator->ProcNodeList[TopLevelProcNodeIndex].Token,
> > +             TopLevelToken,
> >                ScopeNode,
> >                &ProcContainerIndex
> >                );
> > @@ -1106,7 +1108,7 @@ CreateTopologyFromGicC (
> >           break;
> >         }
> >       }
> > -  } // for
> > +  }   // for
> 
> Is it possible to remove this change ?
> 
> >
> >     return Status;
> >   }
> > diff --git
> >
> a/DynamicTablesPkg/Library/Acpi/Arm/AcpiSsdtCpuTopologyLibArm/SsdtCp
> uT
> > opologyLibArm.inf
> >
> b/DynamicTablesPkg/Library/Acpi/Arm/AcpiSsdtCpuTopologyLibArm/SsdtCp
> uT
> > opologyLibArm.inf
> > index 3e2d154749..00adfe986f 100644
> > ---
> >
> a/DynamicTablesPkg/Library/Acpi/Arm/AcpiSsdtCpuTopologyLibArm/SsdtCp
> uT
> > opologyLibArm.inf
> > +++
> b/DynamicTablesPkg/Library/Acpi/Arm/AcpiSsdtCpuTopologyLibArm/Ssdt
> > +++ CpuTopologyLibArm.inf
> > @@ -31,3 +31,7 @@
> >     AcpiHelperLib
> >     AmlLib
> >     BaseLib
> > +  PcdLib
> > +
> > +[Pcd]
> > +
> >
> +gEdkiiDynamicTablesPkgTokenSpaceGuid.PcdForceTopLevelProcessorConta
> in
> > +er